MP4Autotag streamlines the process of tagging MP4 videos on your Mac so you can upload them to video sites -- with tags and other metadata ready to go. It also provides valuable tagging information for display on mobile devices if you are loading up your MP4-compatible tablet, phone, or media player with videos for a long trip or study.
MP4Autotag downloads directly from the developer, allowing you to start it right away, though you'll need to add a security exception to open it in Mountain Lion. After doing so, you can drag and drop an MP4 video to the system and it will attempt to automatically look up the video in thetvdb.com or themoviedb.org. All tags will be dropped to the video if a match is found. If there is no match, you can attach new images, change results, add tags, or rename meta tags or file names from within the interface. Images can also be pulled from the iTunes store if you have personal videos you've copied.
MP4Autotag is a useful piece of software for anyone with large video collections from before modern online directories -- meaning their tags are out of date, missing, or inaccurate. At the same time, you can add tags to your own personal videos just as easily with the streamlined interface provided in the app. It's not a perfect MP4 editing app, but for metadata editing, it works quite well.